In a combined cycle power plant heat is derived from the exhaust gas of one or more gas turbine - generators to produce steam for a steam turbine generator. In such a plant, it is frequently desirable to utilize an afterburner to increase the temperature of the exhaust gas before the gas enters a steam generator. It is further desirable to adapt the gas turbine and its associated afterburner to use at least two fuels, to permit continued plant operation when one of the fuels is unavailable. It is advantageous to transfer gas turbine and afterburner fuel while the plant is operating, to avoid costly shutdown for fuel transfer. The above-referenced applications Ser. No. 495,701 and 495,702 disclose on-line gas turbine fuel transfer systems. The present disclosure is related to coordination of such on-line gas turbine fuel transfer with on-line afterburner fuel transfer.